post #17, 23, 24 .....great info thanks, as "they" answered the question on whether you should use a small base for you AR platform or semi auto.

Matt.

Talking about "conventional wisdom" that isn't: Insinuating that all folks who happen to have AR's that don't feed conventional FL sized reloads well are stupid and can't set sizer dies correctly is flat uncalled for. Once you set the die to cam-over as per most instruction sheets....which is about as hard as buttering bread, tell me, what magic do you have to make bases smaller, so they will chamber without a hammer.

I had one guy on another forum say to grind off your shell plate a little. That's a great idea....then you can bump the shoulder back even further, when a conventional sizer, cammed over, usually bumps it back too much already. Your gauges say you're bumping too much? ...get a small-base and back it out a hair.

Then there's the magazine writer "gurus" who insist small-based sizers work the brass too much. Think a .001 or .002" squeeze at the base is worse than bumping the shoulder back .005" when its not necessary? Sure it is. Besides, the havoc the AR action does to brass will make it unusable long before squeezing the base will.

If I am not given the luxury luxury of disagreeing? I will take it. The small base die does not size the base of the case, again and again! The shell holder has a deck height, the deck height on my shell holders is .125”, the shell holder prevents the die from reaching the head of the case. Meaning the base of the case is not sized, that leaves the rest of the case above .125. Added to the .125 is the radius at the opening of the die. Then there is the not knowing, not knowing WHAT! The reloader should know/ be able to understand the dimensions of the case, the reloader should understand minimum length, full length sized, go-gage length etc., etc..

Then there is: “get a small-base and back it out a hair” sure, purchase another die, I suggest learning to use the die he has before spending money on something he may not need. I just received feed back on a rifle, I delivered it with a new box of Remington ammo, rather than assume anyone understands why I will explain, the new ammo was minimum length, not shorter, not longer, the new ammo was equal in length to full length sized. Point? If in the future reloaded ammo will not chamber I will instruct the proud owner to to learn to operate a press or quit reloading.

What ever rifle is being discussed on this thread has had new/factory ammo fired in it, the new/factory ammo chambered and fired, What happened? When the case snapped back, jumped back or recovered did it stick to the chamber and snap it back also? How did the chamber get smaller.

Then there is the: “usually bumps it back too much already”. With the bragging you are heaping on post numbers 17, 23 and 24 and the wonders of the small base die???? I have to ask, if grinding the shell holder increases the ability of the die to shorten the case from the head of the case to its shoulder, why would he need a small base die? Rational, the case has tapered sides, the case is round, a round case with tapered sides is a cone, shorten the cone the varying diameters of the case are reduced when compared with the chamber, just an opinion but I am wondering if the small base die’s function is understood. I size/form cases for short chambers, if the ‘minimum length/full length sized’ concept was understood the reloader could size cases for short chambers, when forming cases for short chambers I have 12 options between minimum length (.000) and a –.012” short chamber, meaning the chamber is .012” shorter than a minimum length case. Meaning if the case was fired in a go-gage length chamber the difference in length between the case and chamber would be .013”, in my opinion that is too much case travel, I am the fan of cutting down on all that case travel.

It is never necessary to grind the bottom of the die, it is never necessary to grind the top of the shell holder. Redding competition shell holders are never necessary , nice but not necessary. Think about it, $40.00 to replace $6.00 shell holders. 5 sets of 4 shell holders @ $40.00 X 5 shell holders sets = $200.00, then there will be the argument, a reloader only needs one set when sizing cases for the chamber that needs the use of the Redding shell holder, again, the reloader needs to become more proficient with the press, die and shell holder set-up.

Then there is that part about full length sizing to minimum length without a clue or a way to determine if the case was full length sized to minimum length before lowering the ram, it is possible the case whipped the press, or if the press whipped the case. Knowing if my press sized the case before lowering the ram is saves me time in effort, knowing the case will chamber before I lower the ram if a technique I believe a reloader should master before ordering a small base die. Then there is full length sizing, if the reloader knew the length of the chamber they could make a determination, is full length sizing necessary?

I have small base dies, again, I have RCBS BAR dies, my favorite die is the forming/trim die.